A common problem of pneumatic tires is that, while they may be designed to allow smoother riding and higher speeds, the integrity of their membranes more easily and often becomes compromised by, for example, being punctured. Although some tire designs may have thicker tire tread and/or incorporate materials resistant to puncturing (such as polyurethane), due to the limited speeds such tires may often travel, and due to a possibly-less comfortable/smooth ride, and/or the limited puncture resistance actually obtained by such products, standard pneumatic tires remain common for many normal vehicles. However, traveling in vehicles with normal pneumatic tires that have been punctured can be dangerous and cause additional damage to the tire and even other parts of the vehicle (such as the wheel). Moreover, repairing a compromised tire by the traditional and common method of stopping a tire from rotating and removing it using a jack and a tire wrench so it can be repaired (often by patching or plugging, or both) has well-known drawbacks—such as, for example, inconvenience, requiring an excessive amount of time, and jeopardizing the safety of the driver and or passenger. For example, dangerous environmental conditions outside the vehicle such as extreme weather, careless drivers, or a passerby with malevolent motives, can all place at risk the well-being of the driver and passengers.
Some devices for repairing tires have been created to allow temporary repair and inflation of a tire to occur more expeditiously, without having to remove the compromised tire (i.e., decouple the tire from the wheel). For example, a canned tire inflator device attaches to the tire valve, with compressed refrigerant forcing the can's contained sealant into the tire where it may block a puncture, and thereby allow the tire and vehicle to travel some minimum distance to a presumably safer destination. While such devices may be useful in performing the intended function, they also have drawbacks. For example, the sealants used in such devices often contain harmful chemicals, and due in part to the fact that the sealants may enter the hollow tire cavity from a point outside the tire cavity and the wheel, said harmful chemicals may sometimes shoot out of the valve stem at a high pressure level, which might cause injury to the operator and/or others. In addition, such sealant has been known to block or destroy certain technology found in valve stems, and the temporarily-repaired tire must normally still be either fully repaired (using a plug or patch) or entirely replaced with a new intact tire. Furthermore, although the canned tire inflator (and similar devices) may effectively and laudably reduce time required of an operator outside a vehicle, it nevertheless still requires that the operator stop and exit the vehicle for a period of time, thereby subjecting the operator for some amount of time to the same potentially dangerous conditions mentioned above.
Due mostly to safety reasons similar to those mentioned above, some tire designs, often called run-flat tires, have been created to allow a vehicle to continue travel after a tire has become compromised, thus avoiding a driver from having to stop and exit the vehicle altogether. Some self-sealant run-flat tires, for example, may consist of extra lining inside the tire, which lining may incorporate sealant material for sealing punctures of a certain maximum size. Other run-flat tires may incorporate support rings that attaches to the wheels or sidewall reinforcements (of the tires) that may support the weight of the vehicle. Some run-flat tires may include, for example, wheel well fillers or safety bands, which may be mounted inside the wheel wells or tires. One run-flat tire design may include a carcass of un-interconnected inflatable hollow elements that, after one of the hollow elements has been punctured or damaged, may be intended to allow the vehicle to continue traveling while the run-flat tires are in inflated states. Such run-flat tires may also entail obvious disadvantages, such as for example: weighing more than other tires and thereby reducing gas mileage, increasing rolling resistance, providing a rougher ride, and not allowing traveling at higher speeds. In addition, some run-flat designs have more specific application for military use and may not be practical or possible for broader use by civilian vehicles.
Although most run-flat tires and devices, as opposed to the canned tire inflator, do not normally allows tires to be re-inflated (but rather as the name suggests are intended to allow the tires to travel in an at least partially deflated state), some other devices allow inflation of not only a stationary tire, but also a moving tire, or at least without removing/decoupling a tire from a wheel. For example, some older “automatic tire inflation systems” have incorporated long wand-like conduits protruding from an opening in the vehicle frame near the wheel, for connecting to the valve stems of the tires. Other devices of a similar genre have included air channels or lines running through the wheel rim, or allowed engagement with a hub cap or axle, or similar vehicle part. Few inflation devices are entirely internal to the tire, or allow inflation to occur by means that are internal to the tire, and without requiring connecting the valve stem.
Some automatic tire inflation systems and some devices for repairing tires, in order to determine whether tire inflation and/or repair is necessary, may incorporate some means for detecting tire pressure or temperature of a tire. For example, some sensors may detect whether a tire has been compromised by measuring and comparing the tire pressure and/or thermal radiation (temperature) of one tire with that of another tire. A few such detection devices may allow “co-movement” with a wheel of a vehicle (for example, by fastening to the outside of the wheel or valve) to allow monitoring of air pressure to take place even during operation of the vehicle. Among other disadvantages, such placement may possibly cause asymmetrical mass distribution along the wheel, and resulting degradation of wheel balance.
Some wireless sensors also have been created for sensing when a tire has been compromised or punctured, which may be operated using a wireless energy source, such as a battery or a transducer, which (transducer) may receive power either inductively, through radio frequency energy transfer, or capacitively. A few tire pressure monitoring systems may also incorporate a tire pressure sensor placed inside a tire. Nevertheless, few if any such devices detect punctured portions of a tire from a reference point that is internal to the tire coupled to a wheel.